1. Field of the Invention:
This invention is a process for the continuous transesterification of C.sub.6 -C.sub.22 fatty acid lower alkyl esters with polyhdric C.sub.2 -C.sub.5 alcohols in the presence of homogeneous alkaline catalysts.
2. Statement of Related Art:
Hitherto, reactions of methyl esters of fatty acids with polyhydric alcohols, particularly glycerol, have largely been carried out in batch or semi-continuous processes. The end products obtained, particularly triglycerides, may be used as such for a variety of technical applications. Partial glycerides obtained may be converted with water under pressure into fatty acids. The route to fatty acids via the glycerides is advantageous, in relation to the direct saponification of fatty acid esters, because it does not involve any salt pollution of the wastewater.
Transesterification reactions of fatty acid methyl esters with nonohydric alcohols in continuous reaction columns are mentioned in EP-B No. 0 082 301 although there is no reference to any details of the process involved. A synopsis of the transesterification of fatty acid methyl esters with glycerol is published in JAOCS 59, Vol. 10, 795A-802A (1982).